Ok, I have finally actually read this whole thread and there are items I just can't let go.
Great question: let me kick off my answer with a question of my own, presented to you: When do you NEED to log time?
The answer is never unless you need to demonstrate that you've acquired the required flight experience for the next certificate or rating that you would like to get, in which case you would log time.
That isn't entirely true. If you want to exercise your pilot privileges, especially to carry passengers, you also must be able to show currency. As in three takeoffs and landings in the last 90 days.
Then there's always the possibility that the examiner for your next checkride looks at your 8710, notices the Total Time is greater than the sum of the "PIC" and "Dual Given" columns and starts asking questions. I wouldn't want to have to talk my way through that one...
That may be true for the PP checkride, but after that, Dual, or more accurately "Training Received" may also be logged as PIC, so the two won't add up. And, just to pick a nit, the student's logbook would show Training Received, or Dual Received, not dual given.
If you feel that your experience during a flight is useful for the above, or experience adding to your skills in order to act as PIC...then log it.
As long as it fits in a logging cubby hole in 61.51. Otherwise it can't be logged. Period.
If it's a pleasure flight, or just exposure to another environment-inevitably as a pilot/student you are going to pick up some information-but is it really adding to your abilities as a hopeful PIC? If you sincerely think it is and you have future plans, log it. But do so conscientiously.
I am not sure I follow here.
Multi-time hopefuls often get a little overzealous with logging because costs are so high. Safety pilot with another. Both technically log it, but as the safety pilot does it really add to his/her ability to fly/act as PIC of a multi-engine?
1) The safety pilot cannot log PIC unless he is the legal PIC of the flight and has all the currencieds and flight review to go with it.
2) If the safety pilot cannot act as legal PIC, then he CAN log it as SIC.
3) Whether or not it adds to the pilot's ability to act as PIC is rather irrelevant. It IS logable time and should not be discarded. Especially when it comes to the 250 hours for Commercial or 1500 for ATP.
Don't you need log entries to satisfy the recency of experience requirements? I.e. - BFR, IPC, x inst. approaches within x months, x landings within x months, etc?
The answer to this question is you DO if you intend to exercise the privileges of a certificate or rating that require currency or recent experience.
Isn't that EVERY time you turn a wheel on an airplane? If not, examples please.